The crudely made anti-Muslim video that has sparked violent outrage in Egypt and Libya this week was posted prominently Monday on the Web site of a Coptic Christian group headed by a Morris Sadek, an Egyptian American activist and lawyer who lives in Northern Virginia.

The site features a grainy photo of two actors in white turbans, the title “English Muhammad Movie Trailer” and a link to the video on YouTube. Next comes an ad for “International Judge Muhammad Day” on Sept. 11, questioning whether the prophet Muhammad was a “pedophile” and a “deceiver,” and a photograph of Sadek shaking hands with rightist Florida pastor Terry Jones.

Coptic Christian leaders in the Washington region and across the United States have denounced the video as highly offensive and inflammatory, and they have expressed concerns that it could further inflame Muslim sentiment against Copts in Egypt, where the large Christian minority has faced harassment and violence for years.

Federal authorities on Thursday said that a Coptic Christian man in southern California, currently on probation for financial crimes, is the key figure behind the video. According to the Associated Press, government sources said that Nakoula Bassely Nakoula, 55, was the person who wrote and directed the film.